Recent Advances on Social Determinants of Mental Health: Looking Fast Forward

New support for the role of SDOH in mental health has accumulated in the past 5 years. Socioeconomic status continues to predict development of mood disorder, suggesting a reciprocal relationship between the two (8). Several studies (9–11) have identified how income and related events influence mental health, such as economic shocks and mental illness (9). The most compelling causal evidence that poverty causes mental illness comes from randomized controlled trials that evaluate antipoverty programs. Studies of cash transfer and multifaceted antipoverty programs have found substantial positive impacts on mental health, with average effect sizes ranging from 0.067 to 0.138 standard deviations (9). Using a quasi-experimental design, Shields-Zeeman and colleagues (11) demonstrated the association of higher income and larger refunds from the Earned Income Tax Credit with reduced psychological distress (effect size, Cohen’s d=0.032 per $1,000 additional income). Similarly, Weissman and colleagues (10), using the ABCD study of early adolescents, demonstrated that lower income predisposes youths to greater internalizing and externalizing psychopathology and that the generosity of antipoverty programs impacts the size of these associations. Job insecurity, financial concerns, lack of economic stability, debt burden, and household over-indebtedness have all been similarly associated with mental health deterioration (12, 13).

Education is another SDOH with substantial evidence of long-term impact on mental health outcomes. Cohen and colleagues (14) demonstrate how educational attainment at age 25 can predict depression at age 40, even after adjusting for confounders and mediators from childhood, adolescence, and adulthood (college graduates were 17%–37% less likely to develop depression by age 40 compared to those with a high school diploma or less). In a nationally representative German sample, Niemeyer and colleagues (15) found that low education is associated with fewer psychosocial resources to manage daily hassles, identifying a pathway between education and depressive symptoms. The causal link between education and mental health has also been established by studying the effects of an education policy reform in Zimbabwe (16), where the findings show that every additional year of education decreases the likelihood of any symptoms related to depression and anxiety, by 11.3% and 9.8%, respectively.

Employment and work conditions also impact mental health, with evidence that unemployment and job insecurity increase the likelihood of mental health service use (17). This association between job insecurity, financial concerns, and worse mental health outcomes was evident during the COVID-19 pandemic (18). Being very worried about job insecurity appeared strongly tied to depressive symptoms (effect size, Cohen’s d=0.048 when compared with someone not worried at all), while economic worries due to job insecurity led to anxiety symptoms (effect size, Cohen’s d=0.132) (13). Longitudinal data from the European Working Conditions Survey and microdata from the UK Household Longitudinal Survey allowed Belloni and colleagues (19) to confirm the causal relationship between working conditions and mental health outcomes. Higher job quality—such as roles with greater decision-making discretion—are associated with improvements in mental health. In contrast, modifications in the physical environment (e.g., ambient conditions), atypical work schedules, and increases in work intensity can negatively influence mental health.

Food and water insecurity remain powerful SDOH, potentially increasing anxiety and depression symptoms. Food insecurity is associated with 257% and 253% higher risks of anxiety and depression, respectively, compared with no food insecurity (20). In a systematic review, Arenas and colleagues (21) showed that food insecurity creates increased risk for depression, anxiety, and sleep disorders. A review by Myers (22) also showed the link between food insecurity and psychological distress in longitudinal and cross-sectional studies from multiple countries. In parallel, the importance of water insecurity was exposed when 100,000 families who were disconnected from water and sanitation services in Detroit, after falling behind on payments following increases in costs, displayed a significant increase in psychological distress (23). Ethnographic and qualitative studies reveal similar patterns (24, 25).

Housing instability, dangerous or poor housing conditions, and affordability also affect mental health (26–28). Work by Padgett (29) demonstrates the bidirectional nature of housing instability and homelessness with mental health, emphasizing the misconception that most homelessness is due to mental illness. Structural problems causing homelessness can be tied to mental illness. Additional evidence correlates difficulties with housing affordability and worse mental health (30). Lack of access to outdoor spaces, living in denser households, and living alone have also been shown to have a significant association with worsening mental health, in a study of Danish youth in the COVID-19 lockdown (31).

Affordable health insurance coverage is another social determinant that affects mental health problems by improving mental health service access (32). Medicaid parity has been repeatedly labeled an SDOH. Eligibility expansions through Medicaid Section 1115 waivers can also aid with housing transitions, peer services, and nutritional counseling, as examples of how these waivers may represent SDOH impacting mental health (33, 34). Lack of access to prevention and treatment in mental health care, also an SDOH, disrupts opportunities for recovery for people in poor communities.

Structural violence, which occurs whenever social structures perpetuate social inequities (i.e., institutionalized racism, sexism, and classism, among others) (35), is another SDOH with consistent evidence of its impact on civilian well-being in conflict-affected areas (36). Yet, the impact of structural violence is not limited to conflict, but can be reproduced to maintain inequalities within and between social groups, such as in forced or displaced migrants, who show poor mental health linked to oppression and loss of autonomy (37). Relatedly, childhood adversity, like toxic stress, sexual abuse, or neglect, can impact psychological health later in life, becoming a significant SDOH (38). It can have deleterious effects on children’s behavioral and emotional problems, such as aggressive or violent behavior, difficulties in relationships with others, and risk taking. Results demonstrate a dose-response relationship between reported adverse childhood experiences (ACEs) and mental health–related outcomes, with individuals having two or more ACEs showing more than twice the risk of clinically significant psychological distress compared to those without any ACEs (39). However, there are many methodological limitations in studies in this area that require further work (40), including lack of diversity in the samples.

Social connectedness proved to be a key SDOH during the pandemic. A seminal study by Haslam and colleagues (41) described how social identities are central in mental health because lack of social identity can lead to social disconnection, while social identity can help people derive a sense of meaning and purpose and obtain support that is critical for maintaining mental health. In contrast, lack of social connectedness during the COVID-19 pandemic was found to be related to self-reported stress, worry, and fatigue (42). The effects of isolation from social networks and reduced interaction and social connections for students during the COVID-19 pandemic have also been correlated with negative mental health trajectories (effect sizes, Cohen’s d range, 0.095 to 0.442) (43). This literature encapsulates why SDOH are so entrenched in mental health outcomes.

In recent years, there has been a growing research focus on the impact of social factors, such as migrant background or residence in urban areas, on the increased development of severe mental illnesses and common mental disorders. For psychotic syndromes, social factors have long been known to have a causal role. Recent findings have confirmed that environmental factors operate on the background of polygenic risk. Genetics and environment act together to push individuals over the clinical threshold for psychiatric disorders. Biological pathways involved in the stress response, such as the hypothalamic-pituitary-adrenal (HPA) axis and immune system, play a role in linking social risk factors to the development of psychotic symptoms. Perceived discrimination and specific ethnic origin are important determinants explaining this association. Being part of a visible ethnic minority increases the risk of developing a psychotic disorder and experiencing a more challenging course of illness (44). In Canada, a retrospectively constructed cohort of almost 2 million individuals with migrant backgrounds and with nonaffective psychotic symptoms revealed that lack of proficiency in the host country language and African origin were social factors associated with increased risk of developing psychosis (45), aligning with the hypothesis of stress mechanisms (in the form of cultural and social stress) as main drivers for developing the disease. Social factors such as urbanicity and being part of a minoritized group are now considered new measures for predicting individual severity risk for asymptomatic individuals. The environmental risk score for psychosis uses an estimate of the cumulative load of all established environmental risk factors to provide a more accurate assessment to predict psychotic symptoms among asymptomatic individuals. The aggregate combines obstetric complications, paternal age, and specific social factors, such as exposure to cannabis at an early age, childhood adversity, urbanicity, and ethnic minority background, into a single risk score (46). The predictive model is still limited to research purposes and requires further analysis exploring intercorrelation effects of its included risk factors and validation studies, particularly in its accuracy and usability in clinical settings and with non-studied populations (e.g., individuals living in the Global South). Nevertheless, it represents a significant advance in recognizing social determinants as critical factors for disease onset.

In recent years, research in the United States has emphasized the role of minoritized ethnic/racial identity as a risk factor for psychosis (47). However, progress in this area in the United States is still limited compared to other European countries, such as the United Kingdom. In 2021, the Journal published a literature review (48) finding that collective and individual trauma exposure, perceived discrimination, and neighborhood violence are among the risk factors that may explain the higher incidence of psychotic symptoms among minoritized racial/ethnic groups in the United States. The authors called for greater support from academic and research institutions for training and funding to address structural racism and study the underlying mechanisms linking environmental factors with psychosis outcomes.

For other severe mental illnesses, such as bipolar disorder, there have been efforts to set the basis for future research with several published literature reviews and meta-analyses (49, 50). There is a relationship between ethnic minority status and urbanicity and disease onset, along with childhood adversity and substance use exposure. However, further research is still needed to investigate the causal pathways and underlying mechanisms between social determinants and disease onset. Essential findings from the Boricua cohort study (51) detail the mechanisms that impact mental health outcomes. Using a robust causal inference framework, the study shows a striking difference between the incidence of bipolar disorder among young adults from minoritized ethnic groups and those from non-minoritized groups in the United States, with double the incidence of the disease in the minoritized group (incidence rate, 2.22 new cases per 1,000 person-years in minoritized settings, compared with 1.08 new cases in non-minoritized settings). Acculturation stress (i.e., stress associated with adapting to a new culture that is different from one’s own), as reported by caregivers, seems vital in triggering the disease onset.

For more common mental disorders (i.e., depression, anxiety, and substance use disorders), the COVID-19 pandemic has been an extraordinary natural experiment demonstrating the importance of social factors in the development and course of mental disorders across the lifespan (52). Around the world, large-scale restrictions on everyday life were imposed to contain the epidemic, affecting social connectedness, housing stability, and social support. They included isolation periods at home, working from home, limiting physical contact, wearing masks, and avoiding social gatherings and significant social events such as weddings, newborn celebrations, and funerals (53). An extensive review of population-based surveys in 14 countries found that despite minimal methodological differences, population-level mental health (i.e., depression and anxiety symptoms) worsened after the restrictions. The prevalence of clinically significant (i.e., moderate to severe) depressive symptoms ranged from 14.8% to 57.9% (with the highest percentage in the United States), and generalized anxiety symptoms from 8.8% to 47.2% (52). As social restrictions affected the whole population, none of the surveys had a contemporaneous unexposed comparison group. The most common comparators were data from 1) similar populations from the same setting, using the same measures seen in previous robust surveys; 2) closely spaced repeat waves, documenting changes as different COVID-19-related orders were imposed; and 3) regions within the country with higher, lower, or negligible infection rates (54–57).

Worsening mental health symptoms were seen during the pandemic, with substantially higher odds of clinically significant depressive and anxiety symptoms associated with fear of COVID-19 infection, job loss, and the high negative impact of COVID-19 restrictions on daily life (58). When mediation and moderation analyses were applied, job instability was found to be an essential mediator, and psychological inflexibility was a main moderator of clinically significant mental health symptoms (52, 59). The pandemic affected access to treatment, directly impacting the engagement and course of all mental disorders. Beyond COVID-19-related social factors, relevant research on the underlying causal mechanisms for the development of mental disorders found that perceived discrimination, youth-peer relationship, and parent-child relationship mediated the relationship between being part of a minoritized group and the development of anxiety and depressive disorders (60).

Social determinants of health, especially race/ethnicity–related factors, are central to understanding the current data on recovery rates and engagement in mental health and behavioral health treatment. Being part of a minoritized ethnic group, perceived discrimination, perceived social position, and social capital, among other social constructs, are variables increasingly considered in studies of treatment engagement, access to medication, risk of relapse and rehospitalization, comorbidity, and recovery (61–64). Racial and ethnic disparities in mental health are still prevalent and negatively impact the course of mental disorders. Some of the main findings from recent years show higher symptom severity and lower rates of care among older adults from minoritized ethnic groups with depression (65), lower rates of treatment completion for substance use disorders among Blacks and Hispanics compared to Whites in the United States and, in the United Kingdom, higher comorbidities, lower levels of long-term recovery, and less access to and engagement in psychosocial treatment among individuals with psychotic disorders from racial/ethnic minority groups (66–68).

Overall, there is a growing interest in studying the origins, impact, and potential remediation strategies. Scientific journals are launching special issues dedicated to this topic, and the National Institutes of Health is issuing calls for research proposals. Academic institutions offer seminars and specific master’s programs on health equity and social determinants of health. Medical associations are focusing their annual conferences on the issue of racial and ethnic disparities and their impact on mental health outcomes. Although this trend is gaining momentum globally, the United States is at the forefront of this emerging field.

Addressing social determinants of mental health necessitates interventions impacting the social and political conditions shaping health and mental health outcomes, as well as interventions that mitigate the impact of mental health conditions on social risks. The first category includes population- and community-level interventions, including those delivered “upstream” prior to the emergence of mental health symptoms, promoting well-being and addressing key social determinants such as poverty, racism and discrimination, food insecurity, lack of housing, and unemployment (69–72). The second category includes interventions designed for individuals experiencing mental conditions and focuses on preventing social risks, with one example being supported employment interventions for individuals with severe mental illness to prevent unemployment (73–75). Given the reciprocal interplay across the life course between social determinants and mental health outcomes, these two categories are not mutually exclusive.

In categorizing national- and population-level interventions focused on SDoMH, Shah and colleagues (70) followed a conceptual framework linking these determinants to the United Nations Sustainable Development Goals (76). The resulting categories were demographic, economic, neighborhood, environmental, and social/cultural, and evidence in each category was assessed via an umbrella review of systematic reviews, scoping reviews, and meta-analyses of national and population-level policies and initiatives published between 2000 and 2019 (70). The authors found evidence that welfare benefits can reduce disparities in mental health outcomes due to socioeconomic status and that economic austerity measures negatively impact mental health. These findings are consistent with evidence that changes in income impact mental health and improvements in mental health are most significant when the increase moves individuals out of poverty (77). Lower-quality evidence supported social policies such as unemployment insurance, improvements to warmth (in relation to housing), parental leave and parenting programs, and migration policies (70). Taken together, these findings demonstrate the promise of various social policies and programs to improve mental health, in the context of limitations in evidence needed to select the most promising programs definitively.

Castillo et al. (69) have focused on community-level interventions, defined as multisector partnerships involving community members and/or taking place in community settings. These include multisector collaborative care, early psychosis intervention services (with patients with diagnosed psychotic disorders as well as with community organizations serving individuals with potential early psychosis), school-based interventions, and services addressing houselessness, criminal justice, global mental health, and mental health promotion and prevention. While the authors reviewed potential outcomes at all socioecological levels, they found that most studies focus on individual and interpersonal levels, while community-level effects are less common. The Community Partners in Care and Communities That Care interventions illustrate the potential for multisectoral interventions to impact community-level mental health. At the same time, public policies can facilitate multisectoral collaboration through funding, demonstration programs, prevention campaigns, and initiatives involving community partnerships (69).

Some interventions address a specific population of individuals with mental disorders or serious mental illness. For example, Housing First interventions focus on quickly transitioning unhoused individuals into housing and retaining them, while supported employment interventions focus on accessing and maintaining employment. Multiple studies have established evidence for Housing First interventions in transitioning to stable housing, but there is weak evidence for their impact on mental health symptoms (78). A meta-analysis of the international evidence for supported employment (specifically, the individual placement and support intervention) found that individuals who received supported employment were, overall, 2.40 times as likely (95% CI=1.99–2.90) to gain employment as those receiving vocational rehabilitation, with findings consistent across a range of settings (74). Furthermore, a randomized controlled trial of supported employment (the individual enabling and support model) for individuals with affective disorders found it more effective than traditional vocational rehabilitation in obtaining jobs (42.4% vs. 4.0%; effect size, Cramer’s phi=0.435) and reducing depressive symptoms (effect size, Cohen’s d=0.335) (73).

Despite recognition from public health and mental health fields that social determinants play a significant role in health outcomes for minoritized racial and ethnic groups, there are significant gaps and limitations in this work. The nature of social determinants and the complexity of measuring and implementing structural-level interventions present challenges for research and implementation. Below, we present important points of consideration for addressing these challenges and moving toward solid foundations for this work.

The past 5 years have shown promising advances in efforts to address SDOH. The COVID-19 pandemic highlighted how inequitable social conditions faced by marginalized populations escalated adverse mental health outcomes. As we advance, there is growing potential to build on the SDOH–mental health linkage, continuing with research identifying the SDOH–mental health causal pathways to design and implement innovative SDOH interventions at multiple socioecological levels that ensure mental health equity.